Communication terminals that vary a video stream based on how it is displayed

ABSTRACT

A communication terminal includes a communication module, a camera device, a display device, and a controller. The communication module receives a display characteristic command and an input video data stream from a remotely located other communication terminal and sends an output video data stream thereto. The camera device generates an initial video data stream based on incident light. The display device displays a received input video data stream from the remote communication terminal. The controller generates the output video data stream based on the initial video data stream and a received display characteristic command from the remote communication terminal.

FIELD OF THE INVENTION

The present invention generally relates to the field of communications,and more particularly to apparatus and methods for providing videotelephony.

BACKGROUND OF THE INVENTION

Wireless communication terminals have evolved to include increasinglymore functionality. For example, some wireless communication terminalsprovide video telephony by which users of two terminals can both see andhear one another. Video telephony capable terminals can include a cameraand microphone that generates a respective video stream and audiostream, and which are communicated over a wireless interface to anotherone of the terminals.

Providing video telephony over a wireless interface can be difficultbecause of the amount of data bandwidth that can be needed to send andreceive real time/near-real time video audio streams over wirelesscommunication interfaces that can have significant bandwidthconstraints. In some video telephony applications, wirelesscommunication terminals need to both send and receive real time videostreams, and which can include 10 frames per second. The resulting databandwidth requirements on the wireless interface can exceed those neededfor voice only calls by a multiple of about 5 to 10 times. Such highdata bandwidth may not be readily available when the air interface isshared among many wireless communication terminals, such within aservice area of a cellular base station in a cellular communicationsystem. Accordingly, providing video telephony over an efficientlyutilized wireless communication interface continues to be a challenge.

SUMMARY OF THE INVENTION

In some embodiments of the present invention, a communication terminalincludes a communication module, a camera device, a display device, anda controller. The communication module receives a display characteristiccommand and an input video data stream from a remotely located othercommunication terminal and sends an output video data stream thereto.The camera device generates an initial video data stream based onincident light. The display device displays a received input video datastream from the remote communication terminal. The controller generatesthe output video data stream based on the initial video data stream anda received display characteristic command from the remote communicationterminal.

In some further embodiments, the display characteristic command can beindicative of a resolution at which the output video data stream will bedisplayed on the remote communication terminal. The controller can varya resolution of the output video data stream responsive to theindication by the received display characteristic command of theresolution at which the output video data stream will be displayed onthe remote communication terminal.

In some further embodiments, the controller can compress the initialvideo data stream to generate the output video data stream using acompression rate that varies responsive to the indication by thereceived display characteristic command of the resolution at which theoutput video data stream will be displayed on the remote communicationterminal. The controller can compress the initial video data stream togenerate the output video data stream using a lossy data compressionalgorithm that provides a variable quality of video. The quality ofvideo can be varied responsive to the indication by the received displaycharacteristic command of the resolution at which the output video datastream will be displayed on the remote communication terminal.

In some further embodiments, the controller can vary a frame rate of theoutput video data stream responsive to the indication by the receiveddisplay characteristic command of the resolution at which the outputvideo data stream will be displayed on the remote communicationterminal.

In some further embodiments, the received display characteristic commandcan be indicative of a frame rate at which the output video data streamwill be displayed on the remote communication terminal. The controllercan vary a frame rate of the output video data stream responsive to theindication by the received display characteristic command of the framerate at which the output video data stream will be displayed on theremote communication terminal. The controller can vary a resolution ofthe output video data stream relative to the initial video data streamresponsive to the indication by the received display characteristiccommand of the frame rate at which the output video data stream will bedisplayed on the remote communication terminal.

In some further embodiments, the received display characteristic commandcan be indicative of whether the output video data stream will bedisplayed on the remote communication terminal. The controller canselectively transmit or not transmit the output video data streamresponsive to the indication by the received display characteristiccommand of whether the output video data stream will be displayed on theremote communication terminal.

In some further embodiments, the communication module can include awireless communication module that is configured to receive the displaycharacteristic command and the input video data stream over a wirelesscommunication interface from the remote communication terminal, andconfigured to transmit the output video data stream thereto over thewireless communication interface. The controller can vary a maximumamount of data bandwidth of the wireless communication interface that isused to transmit the output video data stream to the remotecommunication terminal responsive to the received display characteristiccommand. The received display characteristic command is indicative of aresolution at which the output video data stream will be displayed onthe remote communication terminal. The controller can vary a resolutionof the output video data stream responsive to the indication by thereceived display characteristic command of the resolution at which theoutput video data stream will be displayed on the remote communicationterminal.

In some further embodiments, the received display characteristic commandis indicative of a frame rate at which the output video data stream willbe displayed on the remote communication terminal. The controller canvary a frame rate of the output video data stream that is transmittedacross the wireless interface responsive to the indication by thereceived display characteristic command of the frame rate at which theoutput video data stream will be displayed on the remote communicationterminal.

In some further embodiments, the received display characteristic commandis indicative of whether the output video data stream will be displayedon the remote communication terminal. The controller can selectivelytransmit or not transmit the output video data stream across thewireless interface responsive to the indication by the received displaycharacteristic command of whether the output video data stream will bedisplayed on the remote communication terminal.

In some further embodiments, the communication module is configured toreceive an input audio data stream from the remote communicationterminal and to send an output audio data stream thereto. The terminalcan also include a microphone that is configured to generate the outputaudio data stream responsive to incident sound, and a speaker that isconfigured to generate sound responsive to the input audio data stream.

In some other embodiments of the present invention, a communicationterminal includes a communication module, a camera device, a displaydevice, and a controller. The communication module receives an inputvideo data stream from a remotely located other communication terminaland sends a display characteristic command and an output video datastream thereto. The camera device generates the output video data streambased on incident light. The display device displays a received inputvideo data stream from the remote communication terminal according to avariable video resolution and/or a variable video frame rate. Thecontroller is configured to control the display device to display theinput video data stream with a particular one of the variable videoresolutions and/or a particular one of the variable video frame rates,and to generate the display characteristic command so that it isindicative to the remote communication terminal of the particular videoresolution and/or the particular video frame rate at which the inputvideo data stream is displayed on the display.

In some further embodiments, the terminal further includes a userinterface through which a user can generate a command to change a sizeof a portion of the display device that is used to display the inputvideo data stream. The controller can vary the particular videoresolution and/or the particular video frame rate at which the displaydevice displays the input video data stream responsive to the indicationfrom a user via the user interface, and can generate the displaycharacteristic command so that it is indicative to the remotecommunication terminal of the particular video resolution and/or theparticular video frame rate at which the input video data stream isdisplayed on the display.

In some further embodiments, the controller can command the remotecommunication terminal through the display characteristic command tocompress the video data stream sent to the communication terminal usinga compression rate that varies responsive to the indication by thedisplay characteristic command of the particular video resolution and/orthe particular video frame rate at which the input video data stream isdisplayed on the display.

In some further embodiments, the controller can command the remotecommunication terminal through the display characteristic command tocompress the video data stream sent to the communication terminal usinga lossy data compression algorithm that provides a variable quality ofvideo which is varied responsive to the indication by the displaycharacteristic command of the particular video resolution and/or theparticular video frame rate at which the input video data stream isdisplayed on the display.

In some further embodiments, the controller can command the remotecommunication terminal through the display characteristic command tovary a video frame rate of the video data stream that is sent to thecommunication terminal as the input video data stream responsive to theindication by the display characteristic command of the particularresolution and/or the particular video frame rate at which the inputvideo data stream is displayed on the display.

In some further embodiments, the controller can selectively display ornot display the input video data stream on the display device responsiveto a command from a user, and can command the remote communicationterminal through the display characteristic command to stop sending theinput video data stream when the controller does not display the inputvideo data stream on the display device.

In some further embodiments, the communication module comprises awireless communication module that is configured to receive the inputvideo data stream from the remote communication terminal over a wirelesscommunication interface and to transmit the display characteristiccommand over the wireless communication interface.

In some further embodiments, the controller can command the remotecommunication terminal through the display characteristic command tovary a maximum amount of data bandwidth of the wireless communicationinterface that it uses to transmit the video data stream to thecommunication module of the communication terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram illustrating a wirelesscommunication terminals and a cellular communication system that providevideo telephony in accordance with some embodiments of the presentinvention.

FIGS. 2 a-c illustrate different video telephony displays on twowireless communication terminals and the associated data communicatedtherebetween in accordance with some embodiments of the presentinvention.

FIG. 3 is a flowchart illustrating operations for varyingcharacteristics of a video data stream from a remote wirelesscommunication terminal using a display characteristic command, inaccordance with some embodiments of the present invention.

FIG. 4 is a flowchart illustrating operations for varyingcharacteristics of a video data stream that is transmitted to a remotewireless communication terminal responsive to a display characteristiccommand that is received therefrom, in accordance with some embodimentsof the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. However, this invention should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the invention to those skilled in theart. Like numbers refer to like elements throughout. As used herein theterm “comprising” or “comprises” is open-ended, and includes one or morestated elements, steps and/or functions without precluding one or moreunstated elements, steps and/or functions. As used herein the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Embodiments according to the present invention are described withreference to block diagrams and/or operational illustrations of methodsand communication terminals. It is to be understood that each block ofthe block diagrams and/or operational illustrations, and combinations ofblocks in the block diagrams and/or operational illustrations, can beimplemented by radio frequency, analog and/or digital hardware, and/orprogram instructions. These program instructions may be provided to acontroller, which may include one or more general purpose processors,special purpose processors, ASICs, and/or other programmable dataprocessing apparatus, such that the instructions, which execute via thecontroller and/or other programmable data processing apparatus, createmeans for implementing the functions/acts specified in the blockdiagrams and/or operational block or blocks. In some alternateimplementations, the functions/acts noted in the blocks may occur out ofthe order noted in the operational illustrations. For example, twoblocks shown in succession may in fact be executed substantiallyconcurrently or the blocks may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

As used herein, a “communication terminal” includes, but is not limitedto, a terminal that is configured to receive/transmit communicationsignals via a wireline connection, such as via a public-switchedtelephone network (PSTN), digital subscriber line (DSL), digital cable,or another data connection/network, and/or via a wireless interfacewith, for example, a cellular network, a wireless local area network(WLAN), and/or another communication terminal. When the communicationterminal is configured to communicate over a wireless interface, it isreferred to herein as a “wireless communication terminal” and a“wireless terminal.” Examples of wireless terminals include, but are notlimited to, a cellular telephone, personal data assistant (PDA), pager,and/or a computer that is configured to communicate data over a wirelesscommunication interface that can include a cellular telephone interface,a Bluetooth interface, a wireless local area network interface (e.g.,802.11), another RF communication interface, and/or an optical/infra-redcommunication interface.

FIG. 1 is a schematic block diagram of a wireless communication system100 that includes two wireless terminals 102, 104 that are configured tocommunicate data with one another over a direct wireless communicationinterface 106 therebetween, over another wireless communicationinterface 108 through one or more cellular base stations 110 a-b, and/orover another wireless communication interface 112 through a wirelesslocal area network (WLAN) router 114. The wireless terminals 102, 104include a display device 120, a user interface 122, a camera device 124,a controller 126, and a communication module 128.

The camera device 124 is configured to generate a video data streambased on incident light. The user interface 122 can include a keypad,keyboard, touchpad and/or other user input device. The user 122interface can also include a microphone that is configured to generatean audio data stream responsive to incident sound, and a speaker thatgenerates sound responsive to an input audio data stream. Thecommunication module 128 is configured to communicate data over one ormore of the wireless interfaces 106, 108, and/or 112 to another remotewireless terminal 102,104.

The communication module 128 can include a cellular communicationmodule, a Bluetooth module, and/or a WLAN module. With a cellularcommunication module, the wireless terminals 102, 104 can communicatevia the base stations 110 a-b using one or more cellular communicationprotocols such as, for example, Advanced Mobile Phone Service (AMPS),ANSI-136, Global Standard for Mobile (GSM) communication, General PacketRadio Service (GPRS), enhanced data rates for GSM evolution (EDGE), codedivision multiple access (CDMA), wideband-CDMA, CDMA2000, and UniversalMobile Telecommunications System (UMTS). The cellular base stations 110a-b are connected to a Mobile Telephone Switching Office (MTSO) 130wireless network, which, in turn, is connected to a PSTN 132 and/oranother network. With a Bluetooth module, the wireless terminal 102,104can communicate via an ad-hoc network through the direct interface 106.With a WLAN module, the wireless terminal 102,104 can communicatethrough the WLAN router 114 using a communication protocol that mayinclude, but is not limited to, 802.11a, 802.11b, 802.11e, 802.11g,802.11i.

The wireless terminals 102,104 are configured to transmit and/or receivea video data stream with one another and/or with another communicationterminal that may be communicatively coupled thereto through, forexample the MTSO 130 and the PSTN 132 and/or another network. In someembodiments, the wireless terminals 102, 104 are configured to establisha video telephony connection with one another in which they transmit thevideo data stream from their respective cameras 124 and receive anddisplay on their respective display devices 120 the received video datastream. The wireless terminals 102, 104 may also exchange an audio datastream that is generated by a microphone and played through a speaker intheir respectively user interfaces 122. Accordingly, when a videotelephony connection is established through the wireless terminals 102,104, users may both see and hear one another.

In accordance with various embodiments of the present invention, awireless terminals that is receiving a video data stream from anotherwireless terminal informs that other wireless terminal whether or notthat video data stream is being displayed, and, if displayed, it informsthe other wireless terminal of one or more characteristics associatedwith how the video data stream is displayed. The display characteristicscan include an indication of what video resolution (e.g., lines of videoper frame, number of pixels, and/or size indication) and/or what videoframe rate is used to display the video data stream on the receivingwireless terminal. The display characteristics can be communicated fromthe displaying wireless terminal to the transmitting wireless terminalthrough a display characteristic command. These display characteristicsmay vary over time responsive to, for example, a user command throughthe user interface 122. Accordingly, as the display characteristicschange over time at the receiving wireless terminal, it can communicatethe updated display characteristics to the transmitting wirelessterminal.

The transmitting wireless terminal can then selectively transmit or nottransmit the video data stream, and can vary one or more characteristicsof the transmitted video data stream based on the received displaycharacteristic command. As will be discussed further below, thetransmitting wireless terminal may vary the video resolution, videoframe rate, compression rate, and/or quality of video that istransmitted to the receiving wireless terminal based on the indicationthrough the display characteristic command of whether and/or how thevideo data stream will be, or is being, displayed. Accordingly, thereceiving wireless terminal can coordinate with the transmittingwireless terminal to optimize the amount of data that is used in thevideo data stream based on whether and/or how it is to be displayed, andthey may thereby increase the efficiency with which they use the databandwidth of the wireless interfaces 106, 108, and/or 112.

An exemplary embodiment will now be described with reference to theblock diagram and associated methods illustrated in FIGS. 2 a-c, and bywhich the wireless terminals 102, 104 establish a video telephonyconnection therebetween through which users can exchange real time/nearreal time video and voice. The wireless terminals 102, 104 may initiatethe video telephony connection by exchanging display characteristiccommands that are indicative of how a received video data stream will bedisplayed. The wireless terminals 102, 104 respond to the displaycharacteristic command from other terminal by adjusting the videoresolution (i.e., display size), compression rate, and/or quality ofvideo that it transmits.

Referring now to FIG. 2 a, the wireless terminals 102, 104 initiallyexchange voice data streams and full video. As shown, wireless terminal102 displays a large image of the video data stream received fromwireless terminal 104 (VIDEO 2) and a small image of the video datastream that is locally generated by the camera 124 (VIDEO 1). Forexample, the local VIDEO 1 may be displayed in an area of the displaydevice 120 that overlies the VIDEO 2 display area (e.g., apicture-in-picture display format). Similarly, wireless terminal 104displays a large image of the video data stream received from wirelessterminal 102 (VIDEO 1) and a small image of the video data stream thatis locally generated by the camera 124 (VIDEO 2).

Referring to FIG. 2 b, a user commands the wireless terminal 102 to swapwhere the local VIDEO 1 and remote VIDEO 2 data streams are displayed.By swapping the where VIDEO 1 and VIDEO 2 are displayed, the user canobtain an enlarged view of VIDEO 1 which may provide a betterappreciation of how it may appear to another user at wireless terminal104. Accordingly, the local VIDEO 1 is then displayed in the larger areaof the display 120 and the remote VIDEO 2 is displayed in the smallerarea of the display 120. The wireless terminal 102 also notifies thewireless terminal 104 through the display characteristic command thatthe VIDEO 2 which it transmits will be displayed in a smaller area. Thewireless terminal 104 responds to the change in display characteristicsby modifying the VIDEO 2 data stream. The characteristics of the VIDEO 2data stream that can be modified by the controller 126 in wirelessterminal 104 can include, but are not limited to, video resolution,video frame rate, compression rate, and/or other video quality.

The controller 126 in wireless terminal 104 can vary the resolution ofthe transmitted VIDEO 2 data stream responsive to the displaycharacteristic command. Consequently, the controller 126 in wirelessterminal 104 can increase the resolution of the transmitted VIDEO 2 whenthe display characteristic command indicates that VIDEO 2 will bedisplayed on a larger area of the display 120 in wireless terminal 102,and can decrease the resolution when VIDEO 2 will be displayed on asmaller area at wireless terminal 102.

The controller 126 in wireless terminal 104 may decrease the frame rateof the transmitted VIDEO 2 data stream when the display characteristiccommand indicates that VIDEO 2 will be displayed on a larger area of thedisplay 120 in wireless terminal 102, and can decrease the video framerate when VIDEO 2 will be displayed on a smaller area at wirelessterminal 102.

The controller 126 in wireless terminal 104 may use a lossy datacompression algorithm that provides a variable quality of video (e.g.,vary the amount of information in the video) responsive to the displaycharacteristic command. For example, the video data stream from thecamera 124 in wireless terminal 104 can be use a lower compression ratewith a corresponding higher video quality when the displaycharacteristic command indicates that VIDEO 2 will be displayed on alarger area of the display 120 in wireless terminal 102, and can use ahigher compression rate with a corresponding lower video quality whenVIDEO 2 will be displayed on a smaller area at wireless terminal 102.The lossy data compression algorithm can include, but is not limited to,MPEP (moving pictures experts group) and JPEG (joint photographicexperts group) data compression algorithms.

Referring to FIG. 2 c, a user commands the wireless terminal 102 to stopdisplaying VIDEO 2 and only display VIDEO 1. The user may thereby obtainan unobstructed and/or larger view of the VIDEO 1 that is beingtransmitted to the remote wireless terminal 104. The controller 126 inwireless terminal 102 notifies the wireless terminal 104 through thedisplay characteristic command that the VIDEO 2 is not being displayedat wireless terminal 102. The controller 126 in wireless terminal 104responds to the notice by stopping its transmission of the VIDEO 2 datastream, while continuing to transmit the voice data stream. If the usersubsequently commands the wireless terminal 102 to display VIDEO 2, thecontroller 126 notifies the wireless terminal 104 through the displaycharacteristic command that the VIDEO 2 will be displayed at wirelessterminal 102, and the controller 126 in wireless terminal 104 canrespond to the notice by resuming its transmission of VIDEO 2.

Accordingly, the wireless terminals 102, 104 may setup the videotelephony connection by coordinating with each other to optimize theamount of data that is used in the transmitted video data stream basedwhether and/or how it is to be displayed. Then, as one or both thewireless terminals 102, 104 changes how it displays received video, anindication of that change can be coordinated with the other wirelessterminal 102, 104 to again optimize the amount of data that is used inthe transmitted video data stream.

FIG. 3 is a flowchart that illustrates operations for varying thecharacteristics of a video data stream that is received from a remotetransmitting communication terminal using a display characteristiccommand. At Block 300, a communication terminal that is to receive videosends a display characteristics command to the remote transmittingcommunication terminal which characterize how a received video datastream will be displayed on the receiving terminal. At Block 302, thereceiving terminal receives the video data stream from the transmittingterminal. At Block 304, the receiving terminal receives a command from auser to change how the received video data stream is displayed thereon.At Block 306, the receiving terminal modifies how it displays thereceived video data stream. At Block 308, the receiving terminal sends adisplay characteristics command that notifies the transmitting terminalof the modified characteristics with which the video data stream will bedisplayed by the receiving terminal.

FIG. 4 is a flowchart that illustrates operations for varying thecharacteristics of a video data stream that a transmitting terminaltransmits to a remote receiving terminal. At Block 402, the transmittingterminal receives from the remote receiving terminal a displaycharacteristics command which characterize how a received video datastream will be displayed on the remote receiving terminal. At Block 404,the transmitting terminal transmits a video data stream with firstcharacteristics to the receiving terminal. As explained above, the firstcharacteristics of the video data stream can include, video resolution,video frame rate, compression rate, and/or video quality. At Block 406,the transmitting terminal receives a display characteristics commandthat indicates a modification to how the transmitted video data streamwill displayed by the receiving terminal. At Block 408, the transmittingterminal transmits the video data stream with second characteristicsthat are different than the first characteristics. As was also explainedabove, the transmitting terminal can vary, for example, the videoresolution, video frame rate, compression rate, and/or video quality ofthe transmitted video data stream.

In the drawings and specification, there have been disclosed embodimentsof the invention and, although specific terms are employed, they areused in a generic and descriptive sense only and not for purposes oflimitation, the scope of the invention being set forth in the followingclaims.

1. A communication terminal comprising: a communication module that isconfigured to receive a display characteristic command and an inputvideo data stream from a remotely located other communication terminaland to send an output video data stream thereto; a camera device that isconfigured to generate an initial video data stream based on incidentlight; a display device that is configured to display a received inputvideo data stream from the remote communication terminal; and acontroller that is configured to generate the output video data streambased on the initial video data stream and a received displaycharacteristic command from the remote communication terminal.
 2. Thecommunication terminal of claim 1, wherein: the received displaycharacteristic command is indicative of a resolution at which the outputvideo data stream will be displayed on the remote communicationterminal; and the controller is further configured to vary a resolutionat which the output video data stream represents the initial video datastream responsive to the indication by the received displaycharacteristic command of the resolution at which the output video datastream will be displayed on the remote communication terminal.
 3. Thecommunication terminal of claim 2, wherein the controller is furtherconfigured to compress the initial video data stream to generate theoutput video data stream using a compression rate that varies responsiveto the indication by the received display characteristic command of theresolution at which the output video data stream will be displayed onthe remote communication terminal.
 4. The communication terminal ofclaim 3, wherein the controller is further configured to compress theinitial video data stream to generate the output video data stream usinga lossy data compression algorithm that provides a variable quality ofvideo, and wherein the quality of video is varied responsive to theindication by the received display characteristic command of theresolution at which the output video data stream will be displayed onthe remote communication terminal.
 5. The communication terminal ofclaim 2, wherein the controller is further configured to vary a framerate of the output video data stream responsive to the indication by thereceived display characteristic command of the resolution at which theoutput video data stream will be displayed on the remote communicationterminal.
 6. The communication terminal of claim 1, wherein: thereceived display characteristic command is indicative of a frame rate atwhich the output video data stream will be displayed on the remotecommunication terminal; and the controller is further configured to varya frame rate of the output video data stream responsive to theindication by the received display characteristic command of the framerate at which the output video data stream will be displayed on theremote communication terminal.
 7. The communication terminal of claim 1,wherein: the received display characteristic command is indicative of aframe rate at which the output video data stream will be displayed onthe remote communication terminal; and the controller is furtherconfigured to vary a resolution of the output video data stream relativeto the initial video data stream responsive to the indication by thereceived display characteristic command of the frame rate at which theoutput video data stream will be displayed on the remote communicationterminal.
 8. The communication terminal of claim 1, wherein: thereceived display characteristic command is indicative of whether theoutput video data stream will be displayed on the remote communicationterminal; and the controller is further configured to selectivelytransmit or not transmit the output video data stream responsive to theindication by the received display characteristic command of whether theoutput video data stream will be displayed on the remote communicationterminal.
 9. The communication terminal of claim 1, wherein thecommunication module comprises a wireless communication module that isconfigured to receive the display characteristic command and the inputvideo data stream over a wireless communication interface from theremote communication terminal and to transmit the output video datastream thereto over the wireless communication interface.
 10. Thecommunication terminal of claim 9, wherein the controller is configuredto vary a maximum amount of data bandwidth of the wireless communicationinterface that is to transmit the output video data stream to the remotecommunication terminal responsive to the received display characteristiccommand.
 11. The communication terminal of claim 9, wherein: thereceived display characteristic command is indicative of a resolution atwhich the output video data stream will be displayed on the remotecommunication terminal; and the controller is further configured to varya resolution of the output video data stream based on the initial videodata stream responsive to the indication by the received displaycharacteristic command of the resolution at which the output video datastream will be displayed on the remote communication terminal.
 12. Thecommunication terminal of claim 9, wherein the received displaycharacteristic command is indicative of a frame rate at which the outputvideo data stream will be displayed on the remote communicationterminal; and the controller is further configured to vary a frame rateof the output video data stream responsive to the indication by thereceived display characteristic command of the frame rate at which theoutput video data stream will be displayed on the remote communicationterminal.
 13. The communication terminal of claim 9, wherein: thereceived display characteristic command is indicative of whether theoutput video data stream will be displayed on the remote communicationterminal; and the controller is further configured to selectivelytransmit or not transmit the output video data stream responsive to theindication by the received display characteristic command of whether theoutput video data stream will be displayed on the remote communicationterminal.
 14. The communication terminal of claim 1, wherein thecommunication module is configured to receive an input audio data streamfrom the remote communication terminal and to send an output audio datastream thereto, and further comprising: a microphone that is configuredto generate the output audio data stream responsive to incident sound;and a speaker that is configured to generate sound responsive to theinput audio data stream.
 15. A communication terminal comprising: acommunication module that is configured to receive an input video datastream from a remotely located other communication terminal and to senda display characteristic command and an output video data streamthereto; a camera device that is configured to generate the output videodata stream based on incident light; a display device that is configuredto display a received input video data stream from the remotecommunication terminal according to a variable video resolution and/or avariable video frame rate; and a controller that is configured tocontrol the display device to display the input video data stream with aparticular one of the variable video resolutions and/or a particular oneof the variable video frame rates, and to generate the displaycharacteristic command so that it is indicative to the remotecommunication terminal of the particular video resolution and/or theparticular video frame rate at which the input video data stream isdisplayed on the display.
 16. The communication terminal of claim 15,further comprising a user interface through which a user can generate acommand to change a size of a portion of the display device that is usedto display the input video data stream, and wherein the controller isfurther configured to vary the particular video resolution and/or theparticular video frame rate at which the display device displays theinput video data stream responsive to the indication from a user via theuser interface, and to generate the display characteristic command sothat it is indicative to the remote communication terminal of theparticular video resolution and/or the particular video frame rate atwhich the input video data stream is displayed on the display.
 17. Thecommunication terminal of claim 16, wherein the controller is furtherconfigured to command the remote communication terminal through thedisplay characteristic command to compress the video data stream sent tothe communication terminal using a compression rate that variesresponsive to the indication by the display characteristic command ofthe particular video resolution and/or the particular video frame rateat which the input video data stream is displayed on the display. 18.The communication terminal of claim 16, wherein the controller isfurther configured to command the remote communication terminal throughthe display characteristic command to compress the video data streamsent to the communication terminal using a lossy data compressionalgorithm that provides a variable quality of video which is variedresponsive to the indication by the display characteristic command ofthe particular video resolution and/or the particular video frame rateat which the input video data stream is displayed on the display. 19.The communication terminal of claim 16, wherein the controller isfurther configured to command the remote communication terminal throughthe display characteristic command to vary a video frame rate of thevideo data stream that is sent to the communication terminal as theinput video data stream responsive to the indication by the displaycharacteristic command of the particular resolution and/or theparticular video frame rate at which the input video data stream isdisplayed on the display.
 20. The communication terminal of claim 15,wherein the controller is configured to selectively display or notdisplay the input video data stream on the display device responsive toa command from a user, and to command the remote communication terminalthrough the display characteristic command to stop sending the inputvideo data stream when the controller does not display the input videodata stream on the display device.
 21. The communication terminal ofclaim 15, wherein the communication module comprises a wirelesscommunication module that is configured to receive the input video datastream from the remote communication terminal over a wirelesscommunication interface and to transmit the display characteristiccommand over the wireless communication interface.
 22. The communicationterminal of claim 21, wherein the controller is configured to commandthe remote communication terminal through the display characteristiccommand to vary a maximum amount of data bandwidth of the wirelesscommunication interface that it uses to transmit the video data streamto the communication module of the communication terminal.